Yim Hoi-man, Yim Sze-ming and Yim Mei-ki each pleaded guilty earlier on Monday to one count of engaging in corrupt conduct with respect to voting at an election.

Barrister Francis Cheng, representing Yim Hoi-man and Yim Sze-ming, said the two were not passionate about politics, had received no advantages in giving their false addresses and had been unaware of the consequences.

But Acting Principal Magistrate Peter Law Tak-chuen reiterated that vote-rigging was a very serious offence so imprisonment was necessary.

Kowloon City Court heard that in July, the trio submitted their voter registration forms to electoral officials using an address in Mong Kok where they did not actually live. They later voted in the election for the King’s Park constituency of Yau Tsim Mong District Council.

The court heard that the sisters were persuaded to do this by staff at a restaurant whose owner was standing in the constituency. Their lawyers told the court that the three regular visitors to the restaurant did so out of goodwill and did not make any pecuniary gain.

Law said the sentence had been reduced from a three-month term after taking the sisters’ guilty plea into account.

Cheng said they were persuaded to sign the application forms in the restaurant because they wanted to help others.

The sentencing came two weeks after brother and sister Chan Yuet-sun, 40, and Chan Siu-kwan, 44, who, the court heard, worked in Biu’s noodle shop, were also sentenced to two months’ jail, the most severe sentence meted out since the first conviction for vote-rigging in March.They have also been granted bail pending appeal against the sentences.

In March, seven men living in Shenzhen were given suspended jail terms for using a false address to register to vote in Yuen Long. During sentencing, Principal Magistrate Anthony Kwok Kai-on said he would have imposed an immediate custodial sentence on the instigator, Lam Kam-hung, had the 57-year-old not suffered from cancer and undergone major surgery.